Just a (sort-of-quick) reply, to what you raised.
Pumping water reservoirs is done all over Europe, without flooding vast areas, as it simply uses already existing glacial areas that were created by similar processes to begin with. It's not meant to be done in flat areas, certainly, but no-one every said one solution fits everything. There are no silver bullets.
I briefly considered splitting natural gas production and the simpler hydrogen/oxygen production, but then found it just belabouring the point. The idea of turning electrical energy into bond energy is chiefly the same in both cases, they just arrive at it with different means.
Yes, flywheels are for short duration load balancing, of seconds to some dozen minutes. Newer designs actually promise a lot more, given the ever advancing march if science. Plus, see again the point about the "no-silver-bullet" thingy.
As for the shuttle, to split hairs, I never specified it stored the flywheel energy for electrical purposes. Reaction mass is energy, too. But I yield to your point, that I should have been more specific. The main point was, that it can store energy for weeks without significant losses, anyway.
The grid-storage idea currently only falls flat because of the design of the network in most parts of the world, which is geared towards putting energy production facilities smack next to energy utilizing facilities (like coal plants next to aluminium smelters), and isolating these nets from each other, with long switchover times. It's never going to store energy for hours -- but then again, many parts of the net actually have the lowest demand during the night. Which is why power is cheaper at night to begin with (for large consumers, at least).
Even Liquid salt reservoirs with just 6h of time are already enough to cover a night during the shorter nights of the year. Certainly not a factor of 10 difference --- or barely even 2, if you used binary magnitudes.
As for your point about rich/poor people: You forget that companies use most of the power in industrialized countries; it's what makes them industrialized. No-one can tell me, that Google can't afford a few million less net income -- and mid-level companies usually do not need multiple mega watts. Sure, the cost may be large ... but then again, how much did the nations of this world offer as trust coverage for the bad banks from 2008 to today?
Point being: It's our short-sighted greed, that causes us to avoid these expenditures. No-one is going to starve because of a 5% price hike on energy -- which, by the way, is a hike that'll come anyway once fossil fuel gets more expensive. I mean, how much has the oil barrel price risen since 1970? Several thousand percent? Sounds about right.
Also, for a more cynical point, the jobs lost are offset by the jobs gained building this improved infrastructure. Just ask the weavers, spinners and loom operators of the 18th century, what they thought about the automated loom; and look how many jobs were created precisely because of the raised productivity this brought.
